Environmental pollution is requiring the development and implementation of alternatively powered vehicles to supplement or replace present conventional internal combustion powered passenger vehicles. Recent developments in the technology of electric and other alternative energy vehicles allows performance of those vehicles to approach that of internal combustion engine powered vehicles in all areas with the exception of driving range. Using electric vehicles as an example, present battery technology limits the amount of onboard energy storage available for electric vehicles and the likelihood that limited locations having recharging facilities will be available in the near term requires systems integrated in the vehicle to inform the driver of battery status and driving range available or, alternatively, destinations within range of the vehicle.
Various battery management systems have been proposed in the prior art to estimate the state of charge of the vehicle battery and remaining vehicle range. Examples of these systems are described in the paper by C. C. Chan and K. C. Chu, "Intelligent Battery Management System," presented at the Electric Vehicle Symposium 9, Nov. 13-16, 1988 in Toronto, Ontario, Canada and the SAE technical paper by A. F. Burke, "Evaluation of State of Charge Indicator Approaches for E. V.'s," presented at the International Congress and Exposition of the SAE, Detroit, Mich., Feb. 27-Mar. 3, 1989. These systems are typically very limited in the information provided to the electric vehicle user.
For some time navigation systems have been under development for use with ground vehicles. Exemplary of the prior art in this field are U.S. Pat. Nos. 4,926,336 to Yamada, 4,984,168 to Meukirchner, 4,992,997 to Nimura et al. and 5,121,326 to Moroto et al. Information provided by such prior art navigation systems can be of particular use to electric vehicle operators, however, supplementing of data and calculation routines of the prior art navigators to incorporate information critical for electric vehicle operation would allow use of a navigation system to supply information to the electric vehicle operator for energy efficient route planning and alternative route planning where insufficient range is available from the battery pack in the vehicle.
The present invention combines and improves the prior art systems to provide an energy management system for optimum use of an electric vehicle by allowing the driver to select performance modes, driving profiles and destinations while informing the driver of vehicle status, range, navigational route capability and vehicle efficiency control.